Generally, golf is a game in which a ball is hit by golf clubs into holes spread over a location with uneven topography. Since golf courses are mainly constructed at places with uneven topography such as at the base of mountains, considerable expertise is required for the golf club swing. Therefore, prior to playing a round of golf at golf courses, a golfer should practice golf while correcting his/her golf swing or posture at an indoor golf range in order to achieve a good golf swing. At this time, the gofer swing draws a circle and should be performed by stereoscopic motions in which motions of the upper and lower parts of the body, motions of knees, and timing are perfected in connection with a proper grip and a proper address position. The practice is performed with a driver, a short iron, a middle iron, a long iron, and the like. The practice of the golf swing should be done with the correct posture for all swing shots.
However, since a golfer generally practices golf only at flat locations, e.g. in a conventional indoor golf range, he/she cannot sufficiently and satisfactorily practice golf for the purpose of making preparation for actual golf games in which there are various changes in topography such as inclined locations on golf courses. Therefore, a golfer cannot do himself/herself justice in practicing for an actual golf game.
To solve such a problem and to ensure practice simulating an actual golf game, there has been developed a foot plate for a golf swing practice apparatus, in which the slope of the foot plate can be controlled both in a right and left directions and in the fore and aft directions.
For example, Korean Patent No. 10-0358416 discloses a slope control apparatus for a golf swing practice mat, in which a hydraulic cylinder is lifted and lowered by means of a control panel and an oil unit and a lower support plate is connected to an upper slope control plate.
Further, Korean Patent Laid-Open Publication No. 2002-0044130 discloses a slope controllable hitting-zone foot plate for golf practice, in which four supports with spherical recess portions formed therein are fixedly installed on the bottom of the hitting-zone foot plate and hemispherical piston heads that are in point contact with the spherical recess portions of the respective supports are fixedly installed at the distal ends of pistons of four hydraulic jacks controlled by a control unit so as to support the hitting-zone foot plate, thereby controlling the hitting-zone foot plate in various slope directions and at various angles.
Moreover, Korean Utility Model Registration No. 20-0267916 discloses a slope adjusting apparatus for a golf hitting-zone, which comprises an address foot plate including first and second panels pivotably installed through a pivot member; a bottom plate including a gear shaft formed integrally therewith on a constant level at the center thereof and with a first gear portion at one end of the gear shaft, ball bearings equidistantly installed at a predetermined interval with respect to the gear shaft, and ball insertion portions for receiving the ball bearings; a slope adjustor including a driving motor installed to abut against the ball bearings mounted on the bottom plate and having a second gear engaged with the first gear, a first lifting means installed adjacent to the driving motor to adjust the level of the second plate, and an intermediate plate having a fixing portion installed at a position corresponding to the first lifting means to fix the first plate; a golf ball receiving unit having second and third lifting means of which levels are adjusted according to slope changes by the slope adjustor; and a control unit for powering and controlling the driving motor and the first to third lifting means.
Furthermore, Korean Utility Model Registration No. 20-0175850 discloses a slope controllable foot plate for golf practice, in which cylinders are attached to respective corners of top and bottom plates, two pairs of diagonally opposing cylinders are connected through respective hoses to each other so as to communicate with each other, valves are attached to intermediate portions of the hoses, and the valves can be simultaneously opened and closed by a lever exposed upwardly beyond the top plate.
In such a conventional foot plate for a golf swing practice apparatus, the slope of the foot plate can be controlled by means of a fully hydraulic or mechanical type slope control device of the foot plate. However, the fully hydraulic type device has a problem in that production costs are increased, while the fully mechanical type device has problems in that the load is transmitted directly to mechanical parts due to play existing in the mechanical parts themselves when a golfer stands on the foot plate and practices golf, resulting in damage to the motor. Also, a golf club may come into contact with a ceiling of an indoor golf range due to the increased level of the foot plate.